How many 32-33-34 Skylines were made, you said you prefer to buy things that hold there value but you have a r34 GTR, I don't mean to be a smart arse but a investment it is not, that car is a classic low model number collectible, Look at XU1, A9X, GTHO, classic Australian cars with racing history, this is why a ADM R32 GTR holds there value.
Just think, most of these cars that pull the big dollars cost around $5000 when new !